Work

Sporulation temperature effect on germination heterogeneity of individual Bacillus thuringiensis spores through single-cell optical analysis

Year: 2025

Type: article

Abstract: The germination heterogeneity of individual bacterial spores significantly impacts spore viability and has critical implications for sterilization processes, food safety, and infection control. Temperature, as a key environmental factor, influences both sporulation and bacterial growth. This study investigates how sporulation temperature affects the germination behavior of individual Bacillus thuringiensis (Bt) spores at the single-cell level using optical approaches. Multivariate curve resolution-alternating least squares analysis showed that the average levels of Ca 2+ dipicolinic acid (CaDPA), protein, and nucleic acid in Bt spores decreased with increasing sporulation temperature. Spores formed at 22°C showed minimal impact on nonnutrient germination but exhibited slower and less efficient nutrient germination compared to those formed at higher temperatures. However, intensive heat-shock treatment (80°C for 30 min) significantly accelerated nutrient germination in 22°C-spores. In contrast, spores formed at 42°C displayed reduced speeds and efficiencies under both nutrient and nonnutrient germination. Germination parameters revealed that sporulation temperature mainly affected the initiation and duration of rapid CaDPA release and germination rate during nutrient germination, while cortex hydrolysis time remained relatively stable. During CaDPA germination, spores formed at lower temperatures released CaDPA faster. During dodecylamine germination, both initiation time and duration of rapid CaDPA release increased with sporulation temperature. Overall, sporulation temperature modulates key spore components, thereby enhancing germination heterogeneity. Lower temperatures may reduce germinant sensitivity and modify inner membrane characteristics, while higher temperatures may alter the structure of CaDPA release channels and impair nucleic acid synthesis.

Source: Journal of Agriculture and Food Research

DOI: 10.1016/j.jafr.2025.102292

Authors: Huanjun Chen, Xiaochun Wang, Haisheng Ou, Yunkai Zhang, Guiwen Wang

Institutions: Guangxi University, Guangxi Academy of Sciences, Shenzhen University

Language: English

Topic: Microbial Inactivation Methods

Subfield: Biotechnology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Zero hunger

Open Access status: gold

Estimated APC paid: $2,530